DNA/RNA Analysis of Blood and Skeletal Muscle in Patients Undergoing Cardiac Resynchronization Therapy (CRT)

• The general objective of this study is to:

• To identify the molecular pathways that may be altered in the blood and skeletal muscles of the patients undergoing CRT by using transcriptional analysis of the blood and skeletal muscle in these patients
• To identify objective measurable molecular signals, using gene expression profiling, that correlate with clinical improvement in patients undergoing CRT.
• To identify the molecular profile of patients who are most likely to benefit from CRT with improvement of exercise capacity and reversal of cardiac cachexia.
• To identify biochemical pathways involved in cardiac cachexia.
• To identify genes involved in positive remodeling and reversal of apoptotic cascade in the skeletal muscle.

Inclusion criteria

• Patients with poor LV function and an EF of ≤35%
• Patients who are symptomatic with Class II or Class III heart failure on optimal medical therapy.
• Patients with EKG showing QRS duration of greater than 120 ms and meet criteria for Bi-ventricular ICD implantation.

Exclusion criteria

• Patients with other co-morbid conditions which could contribute to cachexia, such as end stage renal disease, ongoing malignancy, chronic or acute liver failure, age greater than 80yrs.
• Patients who are unable to walk and are wheelchair bound or need assistance to walk for reasons other than CHF.
• Patients with muscular dystrophies and myopathies.
• Patients with untreated hyper or hypothyroidism.
• Patients on Dialysis.
• Patients with recent (<12 weeks) revascularization.
• Patients with recent (<12 weeks) myocardial infarction.